Turntable or Triangle

The issue was the subject of a presentation by Chris White at the BRPS committee meeting on 21st October 2011.

It is clear that locos and support coaches from incoming rail tours will
need to be turned on arrival at the Bluebell. If we cannot offer the
facility, it will limit our ability act as a destination. It can also be
used to even out flange wear on our locos, and balance the effects of
weather on carriages.

A turntable is not ruled out for future, but is not currently affordable
(quite apart from the problem of where you'd site it) - options for
obtaining one have been investigated, including an inspection of one
available to us on another preservation site, in need of major repairs.
It's concluded that a repair or a new one (which might be a better
option!) would both cost in the region of £500,000 and that transport,
construction of a pit and installation would cost another £250,000.

A Triangle at Horsted Keynes appears feasible, and is also very useful
in permitting the re-use of the vast quantity of clay and sandstone
capping currently stored at Imberhorne. Using the capping to construct
a spur at HK is a very cheap option. Although we can sell the capping,
people looking to buy it expect it to be delivered f.o.c., and so the cost
to us of following that option would actually be several hundred
thousand pounds. A spur of quite tight curvature (4.5 or 5 chains
radius) between Ardingly and SP lines appears feasible, but might
require slight re-allignment of one or both lines, but if on further
investigation that is not possible, there are other arrangements which
might offer less sharp curvature. Triangles with 5 chain radius were used
by Bulleid Pacifics regularly at Chichester and Branksome, but the study
will include confirmation that the achievable curvature (with the
appropriate gauge-spread) is OK for occasional very low speed use by all
potential visiting engines. Since it would only be for occasional use,
one option for access might be via groundframes released by the single line token, so
hopefully avoiding any alteration to HK signalling plans.

Following agreement from BRPS Trustees that this approach should be
investigated further, a detailed plan for a triangle will now be worked
up. Public access for a nature walk, which is planned to include the
area within the triangle, will remain feasible, and a full ecological
survey (impact on trees and wildlife) will be needed. As with the
existing extension of the Ardingly spur, the new embankment would be
well shielded from the road by mature trees, so it is hoped that
planning permission will be fairly straightforward.

In short this proposal would enable us to accept incoming railtours and
turn vehicles as required, has effectively no substantial cost, and
importantly enables us to re-use the mountain of capping from Imberhorne
for an engineering purpose. It looks like a win-win proposal, and as stated earlier, does not rule out the (expensive and longer term)
possibility of installing a turntable.

Postscript

Horsted Keynes: Turntable rather than triangle
The re-grading of the approaches to Imberhorne Cutting has used up much of the capping material from the tip, so there is now insufficient remaining to construct an embankment to form a turning triangle at Horsted Keynes. In any case, site surveys have shown that the track curvature on such a triangle would be too tight for larger engines, so it appears that any future turning facility will involve the installation of a turntable.